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Added support for glTF2 sparse accessors. 

Refactored Accessors, pulling out reusable bits between those
and sparse accessors' indices / values.
pull/3111/head
György Straub 2020-03-30 14:30:33 +01:00
parent b6b3b39bb3
commit 87e2d3a54d
2 changed files with 154 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

88
code/glTF2/glTF2Asset.h
View File

@ -357,24 +357,46 @@ struct Object {
// Classes for each glTF top-level object type
//
//! Base class for types that access binary data from a BufferView, such as accessors
//! or sparse accessors' indices.
//! N.B. not a virtual class. All owned pointers to BufferViewClient instances should
//! be to their most derived types (which may of course be just BufferViewClient).
struct BufferViewClient : public Object {
Ref<BufferView> bufferView; //!< The ID of the bufferView. (required)
size_t byteOffset; //!< The offset relative to the start of the bufferView in bytes. (required)
inline uint8_t *GetPointer();
void Read(Value &obj, Asset &r);
};
//! BufferViewClient with component type information.
//! N.B. not a virtual class. All owned pointers to ComponentTypedBufferViewClient
//! instances should be to their most derived types (which may of course be just
//! ComponentTypedBufferViewClient).
struct ComponentTypedBufferViewClient : public BufferViewClient {
ComponentType componentType; //!< The datatype of components in the attribute. (required)
unsigned int GetBytesPerComponent();
void Read(Value &obj, Asset &r);
};
//! A typed view into a BufferView. A BufferView contains raw binary data.
//! An accessor provides a typed view into a BufferView or a subset of a BufferView
//! similar to how WebGL's vertexAttribPointer() defines an attribute in a buffer.
struct Accessor : public Object {
Ref<BufferView> bufferView; //!< The ID of the bufferView. (required)
size_t byteOffset; //!< The offset relative to the start of the bufferView in bytes. (required)
ComponentType componentType; //!< The datatype of components in the attribute. (required)
struct Accessor : public ComponentTypedBufferViewClient {
struct Sparse;
size_t count; //!< The number of attributes referenced by this accessor. (required)
AttribType::Value type; //!< Specifies if the attribute is a scalar, vector, or matrix. (required)
std::vector<double> max; //!< Maximum value of each component in this attribute.
std::vector<double> min; //!< Minimum value of each component in this attribute.
std::unique_ptr<Sparse> sparse; //!< Sparse accessor information
unsigned int GetNumComponents();
unsigned int GetBytesPerComponent();
unsigned int GetElementSize();
inline uint8_t *GetPointer();
template <class T>
bool ExtractData(T *&outData);
@ -405,11 +427,63 @@ struct Accessor : public Object {
}
};
//! Sparse accessor information
struct Sparse {
size_t count;
ComponentTypedBufferViewClient indices;
BufferViewClient values;
std::vector<uint8_t> data; //!< Actual data, which may be defaulted to an array of zeros or the original data, with the sparse buffer view applied on top of it.
inline void PopulateData(size_t numBytes, uint8_t *bytes) {
if (bytes) {
data.assign(bytes, bytes + numBytes);
} else {
data.resize(numBytes, 0x00);
}
}
inline void PatchData(unsigned int elementSize)
{
uint8_t *pIndices = indices.GetPointer();
const unsigned int indexSize = indices.GetBytesPerComponent();
uint8_t *indicesEnd = pIndices + count * indexSize;
uint8_t *pValues = values.GetPointer();
while (pIndices != indicesEnd) {
size_t offset;
switch (indices.componentType) {
case ComponentType_UNSIGNED_BYTE:
offset = *pIndices;
break;
case ComponentType_UNSIGNED_SHORT:
offset = *reinterpret_cast<uint16_t *>(pIndices);
break;
case ComponentType_UNSIGNED_INT:
offset = *reinterpret_cast<uint32_t *>(pIndices);
break;
default:
// have fun with float and negative values from signed types as indices.
throw DeadlyImportError("Unsupported component type in index.");
}
offset *= elementSize;
std::memcpy(data.data() + offset, pValues, elementSize);
pValues += elementSize;
pIndices += indexSize;
}
}
};
inline Indexer GetIndexer() {
return Indexer(*this);
}
Accessor() {}
inline uint8_t *GetPointer();
void Read(Value &obj, Asset &r);
};

102
code/glTF2/glTF2Asset.inl
View File

@ -540,36 +540,10 @@ inline void BufferView::Read(Value &obj, Asset &r) {
}
//
// struct Accessor
// struct BufferViewClient
//
inline void Accessor::Read(Value &obj, Asset &r) {
if (Value *bufferViewVal = FindUInt(obj, "bufferView")) {
bufferView = r.bufferViews.Retrieve(bufferViewVal->GetUint());
}
byteOffset = MemberOrDefault(obj, "byteOffset", size_t(0));
componentType = MemberOrDefault(obj, "componentType", ComponentType_BYTE);
count = MemberOrDefault(obj, "count", size_t(0));
const char *typestr;
type = ReadMember(obj, "type", typestr) ? AttribType::FromString(typestr) : AttribType::SCALAR;
}
inline unsigned int Accessor::GetNumComponents() {
return AttribType::GetNumComponents(type);
}
inline unsigned int Accessor::GetBytesPerComponent() {
return int(ComponentTypeSize(componentType));
}
inline unsigned int Accessor::GetElementSize() {
return GetNumComponents() * GetBytesPerComponent();
}
inline uint8_t *Accessor::GetPointer() {
inline uint8_t *BufferViewClient::GetPointer() {
if (!bufferView || !bufferView->buffer) return 0;
uint8_t *basePtr = bufferView->buffer->GetPointer();
if (!basePtr) return 0;
@ -588,6 +562,76 @@ inline uint8_t *Accessor::GetPointer() {
return basePtr + offset;
}
inline void BufferViewClient::Read(Value &obj, Asset &r) {
if (Value *bufferViewVal = FindUInt(obj, "bufferView")) {
bufferView = r.bufferViews.Retrieve(bufferViewVal->GetUint());
}
byteOffset = MemberOrDefault(obj, "byteOffset", size_t(0));
}
//
// struct ComponentTypedBufferViewClient
//
inline unsigned int ComponentTypedBufferViewClient::GetBytesPerComponent() {
return int(ComponentTypeSize(componentType));
}
inline void ComponentTypedBufferViewClient::Read(Value &obj, Asset &r) {
BufferViewClient::Read(obj, r);
componentType = MemberOrDefault(obj, "componentType", ComponentType_BYTE);
}
//
// struct Accessor
//
inline uint8_t *Accessor::GetPointer() {
if (!sparse) return BufferViewClient::GetPointer();
return sparse->data.data();
}
inline void Accessor::Read(Value &obj, Asset &r) {
ComponentTypedBufferViewClient::Read(obj, r);
count = MemberOrDefault(obj, "count", size_t(0));
const char *typestr;
type = ReadMember(obj, "type", typestr) ? AttribType::FromString(typestr) : AttribType::SCALAR;
if (Value *sparseValue = FindObject(obj, "sparse")) {
sparse.reset(new Sparse);
ReadMember(*sparseValue, "count", sparse->count);
if (Value *indicesValue = FindObject(*sparseValue, "indices")) {
sparse->indices.Read(*indicesValue, r);
}
if (Value *valuesValue = FindObject(*sparseValue, "values")) {
sparse->values.Read(*valuesValue, r);
}
const unsigned int elementSize = GetElementSize();
const size_t dataSize = count * elementSize;
sparse->PopulateData(dataSize, BufferViewClient::GetPointer());
sparse->PatchData(elementSize);
}
}
inline unsigned int Accessor::GetNumComponents() {
return AttribType::GetNumComponents(type);
}
inline unsigned int Accessor::GetElementSize() {
return GetNumComponents() * GetBytesPerComponent();
}
namespace {
inline void CopyData(size_t count,
const uint8_t *src, size_t src_stride,
@ -621,7 +665,7 @@ bool Accessor::ExtractData(T *&outData) {
const size_t targetElemSize = sizeof(T);
ai_assert(elemSize <= targetElemSize);
ai_assert(count * stride <= bufferView->byteLength);
ai_assert(count * stride <= (bufferView ? bufferView->byteLength : sparse->data.size()));
outData = new T[count];
if (stride == elemSize && targetElemSize == elemSize) {